Mr Fallows said the building had beautiful exposed beams and rimu floors, which would be restored.
The library is expected to be finished by May 2018, and the administration building by July 2018.
Mr Fallows said the library work was being carried out by W & W Construction, and the administration building work by DML.
Mr McGhie said the entire area of the school was fenced off, and the library housed in a temporary home. The work had caused little disruption to school life.
Mr McGhie said in December work would begin on doing up the boys' hostels.
"They will have a total internal refurbishment, and new hot water and heater systems," he said.